1. Field of the Invention
This invention relates to a tool holder for holding a cutting tool in a machine tool.
2. Prior Art
Various types of tool holders have been previously utilized in the art. One of these types is a spade drill holder which has been known heretofore to be of two types of construction. In one type, the shank is straight which readily facilitates its being clamped into an appropriate clamping device on the machine tool. Thus this type is substantially infinitely adjustable because it can be grasped or clamped at an infinite number of locations along its straight shank. This type of construction has a disadvantage in that there is a possibility that, under heavy loads, the tool holder will be pushed back into the clamping device of the machine tool.
A second type of construction also includes a straight shank, but is accompanied by an integral shoulder that surrounds the shank, for the purpose of butting up against the clamping device. Thus the integral shoulder serves as a positive anti-push-back feature. The disadvantage of this type of construction is that there is but one fixed axial location in which the tool holder, and hence the tool, can be held or clamped.